Plans are moving forward to expand Paul Allen's the Flying Heritage and Combat Armor Museum, approved by Snohomish County. Water protection activists have appealed it, however, claiming it ignores impacts of stormwater pollution.

It's an issue the Sno-King Watershed Council has appealed at the airfield many times.

"And we're seeing it here. So, this is a continuing pattern by the Paine Field airport not to provide stormwater controls and in turn trying to circumvent the rules by using every twist and turn they can," Bill Lider said.

Bill Lider and the Sno-King Watershed Council say stormwater run off will harm protected salmon downstream in Big Gulch Creek, which flows into Puget Sound.

County policy requires stormwater retention infrastructure for any new development valued greater than 50 percent of the current land use value. Because the museum expansion is of minimal value compared to the entirety of Paine Field, the county approved the permits.

But critics say the expansion should be compared to Allen's currently leased property. In that case, it would meet the 50 percent requirement, Lider says.

The museum sent KING 5 the following statement: "The project to expand the Flying Heritage and Combat Armor Museum was approved by Snohomish County and complies with all applicable environmental and storm water management laws."

The City of Mukilteo filed a letter of support for the appeal saying the project "does not adequately address" requirements for stormwater drainage. Mukilteo and the Sno-King Watershed Council believe Snohomish County is incorrectly interpreting it's own policy.

Lider estimates an additional $400,000 in infrastructure would secure safer water.

"So, it's a small amount for a rich person like Paul Allen to pay to be a good neighbor and protect threatened species in Puget Sound," Lider said.